The threshold voltage (Vt) of a field-effect transistor (FET) is the minimum gate-to-source voltage differential that is needed to create a conducting path between the source and drain terminals. Threshold voltage for a field effect transistor (FET) may vary from manufacturer to manufacturer or for the same manufacturer Vt may vary for different manufacturing processes or integrated circuit designs. For the complementary metal-oxide-semiconductor (CMOS) process, Vt can be a well-controlled parameter for a given CMOS manufacturing process. CMOS Vt may vary with temperature and may be used, for example, as the temperature sensing voltage in circuits where temperature compensation is needed. In some example circuits, a diode may also be used for temperature compensation. However, a diode may need approximately 600 mV to 800 mV voltage range to be able to measure temperature over a useful temperature range. In low power supply voltage applications, attempting to use a diode may make the buffer or opamp reading this voltage more difficult to design.